The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Mar. 24, 1992
Filed:
Apr. 25, 1990
Shigeki Sawada, Souraku, JP;
Matsushita Electric Industrial Co., Ltd., Osaka, JP;
Abstract
A method of manufacturing a semiconductor device forms an intrinsic base layer by doping an impurity in the emitter polysilicon electrode into the intrinsic base region of the surface of a semiconductor substrate by heat treatment through the emitter lead-out part hole self-aligned to the base lead-out electrode. Thus, beneath the insulation film of the substrate surface between the base lead-out part hole and emitter lead-out part hole, the outer marginal part of the intrinsic base layer and the inner marginal part of the extrinsic base layer overlap uniformly. Still more, since the diffusion of the impurity by heat treatment is very fast in the polysilicon emitter electrode as compared with that in the silicon substrate, an extremely shallow intrinsic base layer may be formed.